The present invention relates to a processed organic product obtained by processing a raw material containing fibrous organic substances of, for example, organic wastes, such as agricultural residues, food residues and industrial organic wastes given off from factories, through a physico-chemical reaction and a biological or a biochemical reaction, as well as to a process and an apparatus for producing it.
While agricultural residues, food residues and industrial organic wastes given off from factories have hitherto been disposed of by, for example, incineration, landfill, dumping into the sea and so on, they cause environmental pollution and are undesirable. These organic wastes contain various components, such as nitrogen sources, hydrocarbons, minerals and fibrous organic substances. In order to reclaim these components as a processed organic product in a form of food product ingredients, medicinal ingredients, fodder raw materials, industrial raw materials or soil conditioner raw materials, it is necessary to convert them into a corresponding product having physical properties and a chemical composition adapted to each specific purpose, while removing pollutant virulent bacteria, such as pathogenic Escherichia coli, Salmonella, Cryptosporidium and so on. In order to convert the components, such as nitrogen sources, hydrocarbons, minerals and fibrous organic substances, into a raw product suitable for use in food or fodder having well-balanced contents of nutrient components, it may be adapted to have recourse to a biological or biochemical reaction utilizing a useful microorganism, wherein, however, removal of detrimental microbes is difficult by merely relying on the antagonistic interaction between microorganisms.
For the removal of detrimental microorganisms, use of ordinary techniques, such as use of bactericides, pasteurization and so on, is inadequate for eliminating pollution by microorganisms within the organic wastes, as these techniques are only difficultly effective for decomposing solid matters, such as fibrous substances. A heating sterilization using an autoclave or dry heat sterilization may often lead to thermal decomposition of useful components, such as vitamins, etc.
The insoluble components, such as fibrous substances, contained in organic wastes may be utilized as nutrients exhibiting the third functionality. The reclaimed nutrients reveal inferior gustative performance, since the organic wastes may often have been subjected to lignification, so that a product of dietary fiber exhibiting physico-chemical properties suitable for food materials or fodder is difficultly obtainable from organic wastes by ordinary techniques.
The final residue composed of insoluble high molecular weight substances, such as aromatic high polymeric materials and fibrous high polymers, left after extraction of useful components from the organic wastes by ordinary treating practices is in general in a form of a dense mass of powder or pellets and, therefore, is poor in the capabilities of being aerated and of retaining water, so that soil microbes can hardly grow and proliferate therein. For this reason, the final residue is hardly utilized as a soil conditioner or the like and, therefore, has heretofore been subjected to a chemical treatment by sodium sulfite or brought to incineration.
It is considered ideal to admix undamaged foreign soil rich in organic components and in living healthy soil microbes with a land for improving the agricultural productivity or for restoring the land, such as flooded agricultural land with lost surface soil, land becoming a desert, land injured by salt damage or blighted land. In fact, however, reclamation of agricultural land is realized in most cases by bringing mountain soil containing sand and clay onto the land, since soil or better quality and rich in humus, as found in a broadleaves forest, is difficult to obtain in a large quantity. This land reclamation with mountain soil may often form compacted dense soil blocks after being tread down by cultivating vehicles and so on to build up water-impervious zones, since the mountain soil have a low content of organic matter, and are not adapted for the growth of soil microbes with lower air permeability and water-retentiveness, resulting in inferior aspects in germination rate and in root growth, together with simplification of the soil ecosystem, whereby decreased resistance to injurious microorganisms is brought about with the accompaniment of poor agricultural productivity.
On repeated cultivation of identical crops over several years, the land will suffer from proliferation of injurious organisms, such as nematodes, phytopathogenic bacteria, viruses and insects. For preventing damage by these injurious organisms, use of agricultural chemicals and rotation of crops may be effective. However, there is a demand for crops without using agricultural chemicals or with a reduced use of chemicals in view of growing public interest in the prevention of injuries from agricultural chemicals, so that use of such chemicals should be avoided. Cabbage, white rape, broccoli and the like, which constitute main vegetable crops, belong to the same family as Cruciferae and are prohibitive for crop rotation. In the past, stalks, leaves, roots and so on of such crops are disposed of by incineration for prevention of spread of blights. From the point of view of environmental pollution, however, incineration is problematic, so that an innovative technique for eliminating injurious organisms is needed.
For improving soils having a poor organic matter content, application of organic compost to the soil has been practiced, however, preparation of compost results in an accompanying difficulty in stabilizing the composition thereof and may often suffer from superfluity of nitrogen and phosphate. In addition, when the fermentation of the compost is insufficient, proliferation of injurious organisms, such as pathogenic coliform bacilli, Salmonella, pathogenic parasites and so on, prevails, which may occasionally provide a cause for unfavorable human disorders of food poisoning and the like via crops.
In a practice of preparing organic manure, a compost may be prepared by subjecting excrement of livestock to spontaneous fermentation, wherein it is difficult, however, to control the maturation and the composition and, if the maturation is insufficient, the compost will rot after application to the field to thereby produce ammonia and hydrogen sulfide injurious to young seedlings with the simultaneous breaking down of the microbiotic balance in the soil, giving birth to a fear of occasional pollution of the soil by pathogenic microbes and others. The so-called compost method, in which food residues and so on are subjected to the action of a useful microorganism, such as actinomycetes, nitrogen fixation bacterium, mold fungus or so on, is simple and convenient, but may also suffer from difficulty in the control of maturation and the composition with concomitant fear of proliferation of pathogenic bacteria, as in the compost preparation technique mentioned above.
For subjecting organic substances to a biological or biochemical reaction under utilization of a microorganism, enzyme or so on, a bioreactor has been proposed (Japanese Patent Kokai Hei 8-228762), wherein a plurality of screws, each provided with a screw thread which is arranged at the same pitch with each other but in a helicoid of reverse turn to each other, are disposed side by side in the reactor and each rotated in a rotational sense reverse to that of the neighboring screw so as to draw the contents of the reactor in between the confronting screw threads to thereby force them up- and downwards, whereby the reactor contents are subjected to an action of axial tearing, breaking down and agitation. By this reactor, however, fibrous tissues may not sufficiently be subjected to the actions of axial tearing and breaking and may sometimes be left unbroken, which may be due to the construction of the screws in which they each have a screw thread of the same pitch and are rotated so as to guide the reactor contents in the same direction.
An object of the present invention is to provide a processed organic product and a process and an apparatus for producing such a processed organic product, in which fibrous tissues contained in the raw organic material can be loosened, split and subjected to a breaking action to thereby cut them into short fragments and, further, to biological or biochemical partial digestion, so that raw materials containing longer fibrous organic substances, such as plant bodies, can be used directly for the processing and subjected to a physico-chemical reaction and a biological or biochemical reaction, whereby it is made possible to produce a processed organic product which contains organic matter having a superior nutrient balance while excluding injurious microorganisms and possesses better water retentive performance and better gas permeability.
The present invention resides in a processed product of organic material and in a process and an apparatus for producing the product, as given below:
(1) A process for producing a processed organic product, comprising
supplying a raw material containing a fibrous organic substance to a reactor provided therein with a plurality of main screws arranged side by side so as to confront the peripheral edges of the screw threads of neighboring screws with each other such that each acts to forward the reaction mixture at a velocity different from each other and
effecting a biological or biochemical reaction therein while subjecting the fibrous organic substance to splitting and breaking by the main screws.
(2) The process as defined in the above (1), wherein cooperative screws operative to forward the reaction mixture in the direction opposite to the forwarding direction caused by the main screws are arranged neighboring the delivery end of the main screws, so as to permit the processed product to be taken out in a compressed state.
(3) The process as defined in the above (1) or (2), wherein auxiliary screw(s) operative to forward the reaction mixture in the opposite direction to that caused by the main screws are arranged neighboring the main screws to facilitate the convection of the reaction mixture.
(4) The process as defined in any one of the above (1) to (3), wherein the reaction is an anaerobic or aerobic reaction.
(5) A processed organic product obtained by a biological or biochemical reaction of a raw material containing a fibrous organic substance in a reactor provided therein with a plurality of main screws arranged side by side so as to confront the peripheral edges of the screw threads of neighboring main screws with each other such that each acts to forward the reaction mixture at a velocity different from each other, while supplying the raw material to the reactor so as to subject the fibrous organic substance to splitting and breaking by the main screws.
(6) An apparatus for producing a processed organic product, comprising
a reactor for effecting a biological or biochemical reaction,
a raw material supply port for supplying a raw material containing a fibrous organic substance to the reactor,
a plurality of main screws arranged in the reactor side by side so as to confront the peripheral edges of the screw threads of neighboring main screws with each other such that each acts to forward the reaction mixture at a velocity different from each other and
a processed product exit port disposed on the reactor so as to permit the processed product to be taken out at a location neighboring the delivery end of the main screws.
(7) The apparatus as defined in the above (6), wherein the reactor is disposed in an inclined or horizontal posture, with the plurality of main screws being arranged along the lower wall face of the reactor.
(8) The apparatus as defined in the above (6) or (7), wherein neighboring main screws have helical screw threads and are rotated in reverse rotational sense to each other.
(9) The apparatus as defined in any one of the above (6) to (8), wherein the main screws are designed to forward the reaction mixture at different velocities for each screw by selecting the configuration of the screw thread, its pitch and/or the rate of screw revolution.
(10) The apparatus as defined in any one of the above (6) to (9), wherein cooperative screws operative to forward the reaction mixture in the direction opposite to the forwarding direction caused by the main screws are arranged neighboring the delivery end of the main screws.
(11) The apparatus as defined in any one of the above (6) to (10), wherein auxiliary screw (s) operative to forward the reaction mixture in the opposite direction to that caused by the main screws are arranged neighboring the main screws.
(12) The apparatus as defined in any one of the above (6) to (11), wherein the reactor is furnished with installation (s) having vacant spaces for supporting microorganisms.